Rh-catalyzed 1,4-addition reactions of arylboronic acids accelerated by co-immobilized tertiary amine in silica mesopores
| Autor: | Ken Motokura, Yuichi Manaka, Masayuki Nambo, Wang-Jae Chun, Kohei Hashiguchi, Kyogo Maeda |
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| Rok vydání: | 2019 |
| Předmět: |
Addition reaction
Tertiary amine 010405 organic chemistry Process Chemistry and Technology 010402 general chemistry 01 natural sciences Catalysis 0104 chemical sciences Transmetalation chemistry.chemical_compound chemistry Polymer chemistry Reactivity (chemistry) Amine gas treating Physical and Theoretical Chemistry Phenylboronic acid Mesoporous material |
| Zdroj: | Molecular Catalysis. 472:1-9 |
| ISSN: | 2468-8231 |
| DOI: | 10.1016/j.mcat.2019.04.016 |
| Popis: | Mesoporous silica-supported Rh complex catalysts were prepared by simple silane-coupling, followed by complexation, and characterized by FT-IR, SEM, Rh K-edge XAFS, and elemental analysis. Local structures of the Rh complexes in each sample were almost similar to those of a nonporous silica-supported diaminorhodium complex. Co-immobilization of a tertiary amine on the same silica surface induced slight changes to the Rh complex structure in the case of the support with smaller pores. The prepared catalysts showed high activity for the 1,4-addition reaction of phenylboronic acids. Co-immobilization of the tertiary amine increased the reaction rate by more than 7-fold, with turnover number of nearly 8500. The catalytic performance achieved with this novel system is with much higher than that reported previously with a nonporous silica-supported catalyst. The mesoporous silica-supported Rh complex-tertiary amine showed a wide substrate scope, including unsaturated ketones and nitriles. This co-immobilized tertiary amine may activate phenylboronic acid to enhance its reactivity in the transmetalation step with Rh-OH species. |
| Databáze: | OpenAIRE |
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